A fire has broken out at the famous Notre-Dame cathedral in Paris and has spread rapidly across the building.
The cause is not yet clear, but officials say that it could be linked to renovation work.
A major operation to tackle the blaze is under way at the 850-year-old Gothic building, but the cathedral’s spire has collapsed.
French fire chief Jean-Claude Gallet has told reporters he is not sure if the authorities will be able to stop the fire from spreading.
“If it collapses, you can imagine how important the damage will be,” he added.
Last year, the Catholic Church in France appealed for funds to save the building, which was crumbling.
A spokesman for the cathedral said the whole structure was “burning”.
“There will be nothing left”, he said.
The blaze broke out on Monday afternoon and an area surrounding the building has been cleared.
French President Emmanuel Macron is on his way to the scene and cancelled his planned speech to the nation following the fire, an Élysée Palace official said.
The mayor of Paris, Anne Hidalgo, who is already at the scene described it as a “terrible fire” and urged people to respect the boundaries set up by fire crews in order to ensure that they remain safe.
US President Donald Trump suggested “perhaps flying water tankers” could be used to extinguish the fire.
The Notre-Dame cathedral, which is visited by millions of people every year, is undergoing renovations after cracks began to appear in the stone, sparking fears the structure could become unstable.
Speaking at the scene in Paris, President Macron called the fire a “terrible tragedy”, but added that the worst had been avoided.
He said he planned to launch a fundraising campaign to renovate the cathedral.
“We will rebuild Notre-Dame.”
While there are fears for the many priceless artworks and artefacts housed inside the cathedral, the rector of Notre-Dame, Patrick Jacquin, has told local press that the Crown of Thorns and the Tunic of St Louis have both been recovered.
French Deputy Interior Minister Laurent Nunez has announced that the fire has “decreased in intensity” and “the structure of the building is saved, including the north tower.”